code: def triangular(n):
      """Compute the n-th triangular number."""
      return np.floor_divide(n * (n + 1), 2)
  
file_path: tf-quant-finance/tf_quant_finance/experimental/finite_difference/methods.py
imports: from autograd import elementwise_grad
  import autograd.numpy
  import pandas
  import sobol_seq
label_desc: Use image node_id 6 for calling a global function with example usage: triangular(n) and returns: np